Dough based products, such as crackers, are generally produced by mixing ingredients to form dough, sheeting and cutting the dough sheet into pieces, then baking the pieces. The products may be produced from a dough sheet in many different shapes and sizes. Some dough based products, such as pretzels, can be produced by extruding continuous ropes. These products are generally puffed, and highly expanded, and do not provide a leavened, cracker texture and laminar cell structure (See generally, U.S. Pub. No. 2010/0055284 to Karwowski et al., which is incorporated herein by reference).
Attempts at cracker dough extrusions produced at room temperature (See, U.S. Pat. No. 5,695,804 to Hnat et al.) are known in the art. However, dough variations in the quality and quantity of gluten in the flour can be problematic. These variations can sometimes be controlled through the additions of various non-proteinaceous oxidizing and/or reducing agents such as sulfite, cysteine, and reduced glutathione. These agents can make dough softer, stickier, and less elastic.
Variations in dough extrusion can also affect product characteristics. For example, U.S. Pat. No. 4,959,240 to Aulik et al. describes a process of relaxing a ‘plastic mass’, here a potato based mass, by uniformly pushing the mass at a substantially constant rate through multiple smooth bore passageways of varying pressure (though all less than about 85 p.s.i.g.) followed by a ‘relaxation’ chamber.
High extrusion pressures can also affect product characteristics due to a change in air cells in dough. Generally, the greater the pressure, the lesser the degree of expansion upon subsequent baking or frying and the harder the texture of the cracker or snack.
Other extrusion factors can also be considered. Overworking of the gluten or protein in the dough can result in a ‘glassy’ product texture, rather than a crisp, cracker-like texture. Further, high extrusion temperatures can also result in substantial gelatinization of the starch, which can also lead to a glassy product. Karwowski, et al. describes extrusion pressures of most preferably 20 to 60 psi and temperature range most preferably less than about 100° F. to reduce this glassy texture of the cooked cheese cracker product.
One other important component in the production of an extruded dough is the shape and depth of an extruder die. For example, an in-feed cone having a convex taper and tubular body for the land (where the dough exits the extruder) to reduce dough pressure and friction is known, but can cause damage to certain types of dough structure.